1. Field of the Invention
The invention generally relates to arrangements for validating models having incomplete information. More particularly, the invention relates to arrangements for validating Multi-Stakeholder Distributed Systems (MSDSs) having nodes whose structure and operation are not completely or accurately known.
2. Related Art
Behavioral modeling (of, for example, compute networks or software systems in general) can be applied to help users understand and predict system behavior, to help administrators comprehend and debug configurations, and to help developers better analyze the potential interactions of a new service with its online environment. However, in order to produce results, conventional behavioral modeling requires access to fully detailed configuration and operational data of all relevant nodes of a system. It would be desirable to know in detail (have a model demonstrating) how each node computes its outputs from its inputs, more than a mere I/O description. Unfortunately, for a variety of reasons, node deployers are unwilling or unable to provide complete or accurate data. Thus, a key problem is to design, use, or debug a system while ignorant of how most of its nodes work.
Multi-Stakeholder Distributed Systems (MSDSs) may be defined as distributed systems in which nodes are designed, owned, or operated by different stakeholders in ignorance of one another and with different, possibly conflicting goals. Examples include the email system, networks of web services, telephone networks, the Internet as a whole, and so forth. Such MSDSs have globally inconsistent high-level requirements, and therefore have behavior that is impossible to validate according to the usual meaning of the term. In general, as the term will be used in this disclosure, a “validation process” may be a process in which a client (such as, for example, a human user) states a requirement describing a system behavior, and in which a validation tool/method then evaluates whether the system meets the stated requirement.
All users, administrators, and developers of networked services, in either the public Internet or within corporate or government intranets, face the problems mentioned above. Thus, there is a need for a technique for tolerating incomplete data in the validation process, so that benefits of behavioral modeling can still be obtained, even though node deployers are unwilling or unable to provide complete or accurate data.